Sheet length indicator for cutoff knives



MayZZ, 1945. T, s HTCHETT 2,376,763

SHEET LENGTH INDICATOR FOR CUT-OFF KNIVES Filed Nov. 25, 1943 Sheets-Sheet 1 MTIYESS.

Patented May 22, 1945 Thomas S. Fitchett, Glenarm, Md., assignor to F. X. Hooper Company, Inc., Glenarm, Md., a

corporation of Maryland Applica'tionNovember 25, 1943, Serial No. 51'1,716

10, Claims.

The invention relates to a cut-off knife for corrugated board and similar box material, the same being adapted to the cutting of a moving web, forming sheets or blanks, mainly for use in the manufacture of knock down boxes. The machin shown is of the rotary type to which the paper web is fed at a constant speed, the speed of the knife being controlled and changed to give the number of cycles or cuts per unit of time essential to the desired length of the blanks or sheets, and also in the most approved form to change the speed of the cutters within each cycle at the time of cutting to conform the speed of the cutters to the speed of the paper. f

In the rotary type of machine shown and in other machines for the same purpose, the web passes freely by the cutting blades or knives at .all times, except when they are in cuttingengage ment with the web, the gearing which drives the cutters being of types well-known in the art which give the desired change within each cycle, for comforming the speed of the cutters to the speed of the paper, giving a smooth even cut. This gearing or mechanism is in turn driven by a change speed gear which is adjustable to determine the length of the sheet to be cut byregulating th number of cycles of the cutter'motion for unit of time, the speed of the web as aforesaid being constant. j

For this latter purpose, well-known change speed units are usable as th Reeves drive or a similar but more positive device known as P. I. V. and usually described as positive and infinitely variable or positive, infinite, variable, made by Link Belt Co., other makes being presumably available.

In both types, the speed changing'elements in clude a belt of tapering cross-section, connecting driven elements, each of which elements consists of a pair of correspondingly tapered pulleys, the pulleys of each pair being moved oppositely, in

axial directions, each toward and away from the other, changing oppositely the effective radius of the driving and drivenpull e'ys'.

These changes of speed are-effected by an justing screw which controls thespacing of the respective pairs of pulleys,'and is operatable from outside of the change speed gear casing, but it th minimum chance of error and hence the minimum waste of material. A condition that must be met is that the required'change of the position of the pointers on the indicator dial which is necessary to make the desired change of sheet'length, must be obvious to the degree of intellect possessed by the average operator. The changes must be almost instantaneous and made while the machine is running.

According to the regular practice in the manufacture of corrugated paper boxes, the blanks vary in length by difierences of one inch or fraction thereof from a minimum of twenty-fivev inches to a maximum of one hundred and eighty inches. 155 one-inch graduations as suitable sub-divisions on the dial. It has been found most effective in obtaining the highest degree of efficiency and economy of operation of the machine to have all the graduations spaced Well apart,'and to have the spaces uniform, andfurther it has been discovered that aspacing of the marks or graduations' directly corresponding to the differences between successive sheet lengths-in the series being followed is most efiective in avoiding errors in setting. At the speed of the present machines, a

s such errors, if discovered immediately, are expen- "connected to the change speed adjusting screw by a compensating device, whereby the rotation of the adjusting screw. from the minimum sive in the resulting waste of corrugated paper or other material, and if not detected immediately, involve extensive losses in each instance.

The device of the invention as shown, has graduations spaced by uniform" 1 inch intervals, i. c. Tequal to the diiferences in sheet lengths, and

arranged in a helical line on a small rotatively mounted cylinder which is connected by a reducin'g gear, to a screw which'moves a pointer over the surface of the cylinder, and the cylinder is length to the maximum length cutting positions moves the pointer in parallelism with the, axis, and rotates the dial, causing the pointer to pass over the surface of the cylindrical dial on a substantially helical line, which in the'present instance is the .line of said graduations, 155

inches long, in the preferred form and divided cators are difiicult for the average operator of these machines to use correctly.

The purpose of the invention is to provide an into equal spaces, each division being in said preferred form, suitably marked with the total lengths in inches of the corresponding sheets, each space representing accurately a corresponding .change'in the-length of-sheet being cut by the machine,

There must therefore be approximately change of radius corresponding'to the required compensation, said pulley being on or directly;

cylindrical or other suitable pulley, affording a driven by the change speed adjusting screw shaft,- I V the other end of the cable being wound on a:

helical path for the cable. The latter pulley is-l0 shown as integral with the dial cylinder, various u "30 which meshes with and drives a relatively changes of this arrangement giving the same} result being contemplated. In the drawings,

Figure 1 is a diagrammatic view, showing the relation of the parts in thecembination which is Y the subject of theinvention.

i ure 2 is a side elevation of the dial cylinder and corelated parts.

Figure 3 is a perspective view of the cut-off machine with the sheet, length blank indicator and control in its operative relation thereto.

Referring to the drawings by'numeral-s, each of which is used to indicate the same or similar;

parts in the difierent figures; and having particular reference to Figure 1; the cutter cylinders I and 2, for which. other suitable mounting of the 1 cutters may be substituted are driven by gearing 3, contained within. the casing 4 of which the;

disclosure of PatentfNo. 12,052glfi1t 0f August 25, 1936, is an example, other drives being usable.

In the form shown, the" cutter drive or gearing 3 is driven from a pinion 5, secured to a shaft 1 6 whichfis in turn driven by a Reeves drive or other'similar type ofv change. speed of which the I and 8, mounted, on parallel shafts 6 and 9 with 1 which shafts the, pulIeysare-enga'ged in driving 1 relation, being howevenil slidable longitudinally;

of the shafts.

3 The change speed gear illustrated which is? found satisfactory showstwoshiftinglevers II and i2, 'pivotally mounted intermediately of the 5 length of each' at, M on. asu tame supportwhich 5 i is stationary in the casingIS. Each of-these 1 levers isconnected to corresponding pulleys of i i the respective pair's'land 8,"and their'endsfwhich away from'the other,for'purpos'es more fully f hereinafter discussed;

I project beyond the pair of pulleys 8 are engaged L In the form shownfthe'shaft'9,"which may tomarily' driven from'the usual power shaft by be regardedas driving the machine through the 1 i a belt running on said pulley; fl'Thecorrugator or othermachine which suppliesthe web to the 1 machine just-'descrihed'which; is referred'to as a i chine delivering a paper web to the cut-off knife 20in predetermined positive relation to the speed F" cut-off knife 20', is. connected in any suitable 1 1 manner-as by bevel gears l8, to driving shaft I9 which drivesthe corrugator or equivalent maof shaft 9-.

The adjusting screw' lfij as sho wn, is mounted in' suitable bearings IS" inthe: change speedge'ar' 2376763 hand crank or the like. In the form shown, it I is rotated for the purpose of changing the speed of shaft .6 by means of a motor 2}, the shaft 22'of'which is threaded in the form of a worm which engages and drives a worm gear 24 on and "in driving relation to a 'transverse'shaft 25 parallel to .the screw. [8. This shaft carries a sprocket 25'" which drives a sprocket chain 21 which in turn engages a sprocket 28 on the adjusting screw 1 shaft I6,- and drives the latter.

fIhisshaft'16 carries secured thereto a pinion large gear3|- shownas an internal gear which as illustrated rotates on a shaft 32, parallel to the screw I6. This internal gear 3|, the exact formbeing immaterial, is. shown, as secured to a spiral pulley 33. r

Thisspiral pulley 33 the arm or the -inven'- end of the pulley 33 and thuswinds up' on the I pulley, the take-up of the cable by the pulley increasing in proportion to the rotationof the pulley, and hence of the adjusting screw l6, as the'tangentpoint or-take offpoint of the cable at 34' in the position shown approaches the large end of the pulley. i

In other words,- and more particularly, the radius of the pulley 33, and hence the take-up of the cable 34: increases in, proportion to the decrease of the speed of the shaft 6 as compared to the rotation'of adjusting screw I6 from the position of the parts shown which-is the position for cutting the minimum length sheets, herein designated as 25 inches. I in the position. shown, the cutter-cylinders l and '2 are operated at'a relatively high speed, as

; screw I 6'1 is turned from the limiting position.

shown,,-thus increasing the length of the blanks cut. The 'puuey' 33 and the other parts of the change speed mechanism above described are drawn in proportion and to scale from the blueprints from which applicants machine was made.

Successive points onv the pulley 33 are calculated according to well-known mechanical principles.

to correspond to successive" positions of the belt on the pulleys land 81? The principles ofmathe- "matics and mechanics involved .are, familiar to designers tion. v I

In the form shown, the cable 34 is passed around of machinery and not part'of the invenis preferably a'cylindric'al pulley 38 connectedor secured'to the dial cylinder 39. The cable rotates the cylinder in one direction as'said' cable is ,j roll'ed up in the spiralipulley 3,3;and' a coil spring "E39" keeps the cable under tension and turns the cylinderin the opposite direction;

'This cy1inder'3'9 issecuredito a shaft 49, mounted in suitable stationary'bearings'jdl, on a sup.-

port 42, mounted on the'm'a'chine frame.

In the'form shown, a "gear 4 3 is secured to. the cylinder 39; the same. being; conveniently, about the size of the cylinder. and'a lead screw 44, mounted in suitable; bearings and. turning on an casing l5; and may ifdesi'redbe operatedby a .37; axis parallel to the axisfofQthedial cylinder has In other words,

The speed of shaft Bend the numanv idler or guide'pull'eytfi andhas its other end I wound in a'predete'rmined' path 31 about what secured thereto a pinion 45, meshingwith the gear 43. r

The screw 44, carries a pointer 46, having a suitably apertured end ,4! which moves relatively to the cylinder on a path which is the result of the combination of the pitch of the screw and the relation to each other of gears 43 and 45. This path if traced on the cylinder would be in the nature of a helix.

According to the existing practice in this art, the sheets or blanks vary bydifferences of one inch or fraction thereof from a minimum. which is usually 25 inches to a maximum of 180 inches, and the helical path 48 is graduated in an approximately equal and preferably in precisely equalspace's marked according to the corresponding sheet or blank lengths from 25 to 180, and preferably an inch in length with suitable subdivisions. I

The use of one inch graduations numbered according to sheet length or similar uniform grad-t nations, is found to be of distinct advantage in teaching the average operator, as compared to graduations of varying length for the same purpose and it is also found that in this way, numerous expensive mistakes in settin themachine are avoided. i I The fact that the compensating device 33, 3 3, etc., makes a considerable saving in the size of the dial will be apparent from the fact that it equalizes the length of the graduations and without it, the short graduations being of reasonable and satisfactory length, those which are necessarily longer would be of comparatively great length, requiring a dial'of excessive size which is in fact an existing known difficulty in this art.

The cylindrical dial 39, having the graduations arranged in a helical path thereon also effects a' considerable saving in the overall size of the dial. While a circular dial may be used with a pointer operated by the spiral pulley 33, the dial being marked with one inch orother suitable graduations, and such use is regarded as within the broader scope of theinvention, it is a simple matter of mathematics to ascertain that, with the convenient one inch graduations, such a dial would be about 4 feet in diameter and without the compensating device as the spiral pulley 33, and using a circular dial, if the minimum graduations are of a length of one inch, the maximum length of graduation would be considerably longer, whereby the circular dial would be 6 or 8 feet in diameter, a size which would be wholly unsatisfactory and out of proportion to the size of the machine, and the variation in the length of the graduation would result in numerous expensive mistakes in the nature of incorrect setting of the machine, it being borne in mind that the average operator on said machine is not a mathematician or a scientist and not very alert after spending hours in succession in attending the machine.

In Fig. 3 the motor 55 is for justment to change of speed of the knife in its cutting cycle to conform to the speedof the paper. The switch 56 is for controllingthe motor 55 to determine said adjustment. This is no part of the present invention.

The switches 49, 50, are in circuit with the motor 2| for.operating the same forwardly and in reverse, 52 being a cable containing the'wiring for said switches. This cable 52 isalso indicated in Fig. 1 which is diagrammatic. In the latter figure 54 is a battery or other source of electricity for operating the motor 2|. Such wiring being operating an adfamiliar, no wiring diagram is ideemed necessary i,

In Fig. 3 one cut-off knifeblade isshownat 51 on cylinder 2; the corresponding. knife being shown on the cylinder 1 at 51' l. i

In considering the operation of the-apparatus, it may be noted, it is customary to set the machine while running, and that in so doing, the operator starts the motor 2|, in the proper direc-. tion, turning the adjusting'screw l6, and hence moving the dial 39, andthe pointers until the desired operating position is reached,,which is al-, most instantaneously. In view of the speed with which this change is made, the importance of the equal length graduations corresponding tothe changes of sheet length will be apparent. As soon as the proper number of graduationshas been passed, and the number corresponding to the desired sheet length appears at. the end of the pointer 46, the motor is stopped and if the precise adjustment has not been reached, itmay be further operated, forwardly or in reverse.- A I quickand accurate adjustment is important, as

I during the change, the web and the cut-off knife are running, cutting sheets of varying length which are not usable in the manufacture of boxes or the purposes to which'the cut-off sheet may be put.

A sheet length control and an indicator'therefore, as an example of a satisfactory embodiment of the invention, having beenthus described. It will be understood that. changes within the skill of the average mechanic acquainted with this art are contemplated. i

.What I claim as new and desire to secure by Letters Patent is:

L'The combination with a cut-off knife for making transverse cuts whereby sheets of predetermined, uniformly varying series of lengths are cut from a web, moving at a constant speed in cutting relation to the knife, said machine having means for moving the knife in successive cutting cycles and a change speed gear for driving said moving means to operate the knife in said cycles and a rotatable adjusting shaft for controlling said change speed gear to change the number of cycles per unit of time, the rotation of said shaft having a predeterminable variation relatively to theextent of said changes of speed, of a cylindrical dial having index marks arranged in a helical line and numbered progressively in correspondence with said series of blank lengths, a driving connection from said adjusting shaft to said cylinder, a pointer with means for moving the same along the cylinder in" an axial direction in correspondence with the rotation of the cylinder, whereby the pointer follows said line, said connection from the adjusting shaft to the cylinder, including a compensating device corresponding to said determinable variation, whereby the cylinder rotates in direct cor-' respondence to the changes of the number of cycles per unit of time;

- 2. The combination as in claim 1 in which the spacing of the index marks is equal to the differ-v ences between the successive blank lengths in said series.

3. The combination with a cut-off knife for making transverse cuts, whereby sheets of prede-- termined lengths, comprising a series of uniformly varying lengths, are cut from a Web, moving at a constant speed in cutting relation" to the knife,- said machine havingmeans for moving the knife in successive cuttingcycles and archangespeed :gear for driving said'mean'sto operate the knife in said cycles and a rotatable adjustingshafit for controlling said change speed 1 tochangethe number of cyclesper unit of time, I

the rotation oisaid shaft having' 'a determinable 3 variation, relatively tos'the extent of' successi ve 5 changes of speed, ofa cylindrical dial having index marks arranged substantial-1y in-a helicall path; and numbered progressively in correspond- 1 encewith. said seriesof blank lengths, a pointer with connections to said. shaft for moving the pointer: along saidline in correspondence with thechanges. of sheet lengths; said connection iromrthejadiusting shaft to the pointer, includ ing a; compensating devicecorresponding. ta and adapted to. compensate for said determinable 1 variation, whereby. the pointer moves in direct corresp'ondence'to the changes of the number of cycles per unit of time, and hence with said:

changes, of sheet lengths.

afliThe combination with a'cut-off knife for making-transverse cuts, whereby. sheets of prede-a termine'd lengths comprisinga series of suitably'I varyingleng'ths, are cut from a. web. moving at i a. constant speed inv cutting relation to the knife, said machine having. means for moving the knife] gear for driving said means to operate the'knife in said cycles and a rotatable adjusting shaft for 1 inv successive cuttingcycl'es, and a change speed;

controlling said change speedto; change the mum-f 5 ber'ofcycles per unitof'time, the, rotation of said. shaft having. a determinable variation. relative- 1y to they extent of successive changes of speed;

of a dial having index marks arranged in a line and numbered progressively in correspondence 1 with said series of blank lengths, a "pointer with. 3 connections 'tosaid shaft for moving the pointerv along said line. in correspondence with the:

changes of sheet lengths, said connection fromi ley and a. tensionmember wound; thereon, the" diameten'of the: pulley being varied in corre-l 1 totheskniffe, said machine having. means for mov- 1 ing; the kniie'in successive; cutting cycles, av change speed gear for driving: said means to' operate, the

knife in, said: cyclesfand: a rotatable adjusting shattz for-controlling said change speed gear to changethe number of. cycles per unit of time, of a cylindrical dial having indexmarks arranged";

in. a helical, line and numbered progressivelyinj der rotates in direct proportion tothe changes of the number of cycles per unit of time.

Z; The combination as-per claim '5, in which thechanges of speed have a definite variation,

rela'timely to the extent of rotation "of the adjusting 'sh-aft and said connections from I theadjusting "shaft to the cylinder include a spiral pulley 1 or a radius varying in correspondence with said definite variation, and a tension member wound thereon and driving said cylinder, whereby the cylinder: turnsin direct proportion to the changes of." the number oi cycles per unit oftime. .'8..The combination with-a cut-oil? knifeior making transverse cuts, whereby sheets of 1 prodetermined lengths comprising a seriesoi suitably varying lengths are cut from a web moving at constant speed in cutting'relation'tothe knife, said machine having means for movingthe knife. in successive cutting cycles, a change speed' gear 1 for driving said meansto operate the'knifein said. cycles, and a rotatable adjusting screw shaftior controlling said change speedto change the;

number of' cycles per unit of time, the rotation of. said-shaft having a determinablevariation'rel atively: to. the extent of successive changesof speed-,1 of aldial movably mounted having index marks arranged in a line and numbered progressively in correspondence with said series of blank lengths, a pointer alsomovablymounted with connections to: said shaft for moving the pointer in correspondence 'wi-th 'the changes off sheet. lengths; said. connection from the adjust ing shaft to the pointer includinga compensat-I ing device corresponding tear-idadapted to compensate. forsaid determinable variation, the dial also being operatively connected throughthe com-' p the adjusting shaft to the: pointer including a, $0

compensatmg. device. in. the form of a spiral pub;

I speed gear to. change thenumber of cycles per correspondence with a series of'blank lengths. to v be cut and spaced each from the next by an inter val, a driving connection from-said shaft to said cylinder, a pointer with connectionsz'for moving the same. along. the cylinder in an axial direc-r tion, in correspondence with the rotation oi thecylinder,-whereby the pointer follows said line.

- movab-Iy mounted, whereby the indicatingmeans isoperated to designate indicator, marks'correr,

6 The combination as per claim '5-in' which thechanges 'of speed have a' definitevariation, relatively to the extent of rotation of the'adjusting. shaft and said connections: from the ad dusting. shaft to the cylinderinclude'a'. compensating; deyfceto the adjusting screw shaft whereby the readin is-the resultant of the dial, motion combined with thepointer motion; 9; The combination. as per claim 5 in'which both differences. between successive sheet lengths amdthe intervals on the dial'are one inch in.

length and the index: marks are designated according to; correspondingsheet lengths.

"110;. The-combination with a cut-oif knife for 'making transverse cuts, whereby blanks of predetermined uniformly varying lengths are", cut 1 r from, a webmoving atia constant speed in-cutting relation, to-theknife, said machine having means. for moving. the knife in successive cutting cycles, a substantially constant source of'power, a change speed gear connected to said source and having, av driving connection to saidI rn-"o'vingjv means to. operate the knife in said-cyclesand control, means operatively' connected tosaid change of: time. changingthe blanki q mavement of. said ciontrol'meanshaving a p'rede ten-mined variationrelatively .te the extent of-saidchanges of speed; blank. length indicating means ,includ-i nga diai having spaced index marks berm-progressively in. corrcspondencewith said blank lengths and a pointer, a driving 'connec;

tion from said control to; both the dial andpointer t of said, length. indicating means both of; which are" spending to the. length of blanks being cut,; said driving connectibnirom, the. control. tqlsaid length, 1 d

indicating; .mea'nsji'ncluding a compensating tie-.- vice, perating in corr spondence to-said prede terminedivari'ations, to cause the indicating means:

- pensating device: arranged correspondence definite variaticnpwhereby the cyIin-f oove n. d r c correspondence to the ha 

